textproduct: Quad Cities

KEY MESSAGES

- A near repeat of patchy fog is expected tonight, along with rather widespread low clouds.

- An active pattern will bring showers and thunderstorms to our area starting late afternoon/night, and continuing through the extended. Some severe weather (mainly wind gusts) is possible, as well as heavy rainfall.

- Despite numerous chances for rainfall ahead, there will be plenty of dry hours.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 218 PM CDT Thu Aug 6 2026

Weak convergent low level flow is found over our area today, and has served to keep our skies mostly cloudy today. The modest heating to the upper 70s/near 80 has allowed for some surface CAPE to build today, and some isolated showers/storms are possible, especially near Highway 34 to I-80 today. While 2k SFC CAPE is noted on our 18Z sounding, there's a warm nose at 730mb, limiting the coverage of storms in this weak/zero forcing environment.

We will keep some low pops going for these showers/storms into late afternoon/early evening. Just like last night, the ample moisture near the boundary layer and weak flow favors both low cloud development and fog tonight. We will not go with an advisory yet, as the scale could tip in favor or more low clouds than dense fog in this scenario, but we'll definitely need to keep an eye on that, as we're generally set up for fog if clouds remain thin/scattered tonight.

Friday remains similar to today through early afternoon, with moist conditions and light winds. However, by afternoon, increasing southwest winds will bring in warmer temperatures into the lower 80s north to mid/upper 80s. A few hot and humid hours are forecast in the afternoon, especially south, where heat index reading could reach the upper 90s if they remain sunny. Otherwise, a weak cold front will arrive towards evening, bringing scattered thunderstorms to the region. Coverage remains a concern for these storms, with a nose of warm air aloft and weak forcing. SPC is continuing the level 1, marginal forecast for severe storms. Once storms do form, support from 30+ kts of shear should help organize storms into a cluster/MCS through the late evening. Models are inconsistent on that axis of development, but a stripe of both strong winds and heavy rain is possible in the evening to overnight hours Friday night. Initially isolated damaging winds will be supported by strong instability, but this consolidate to the propagation of any cold pool by mid evening.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 218 PM CDT Thu Aug 6 2026

Saturday another short wave will bring additional chances for storms, mainly into the evening and overnight. These storms will generally have similar support to Friday night, and we'll need to watch for both heavy rain and strong wind gusts.

Sunday and beyond, west/northwest flow is forecast to continue aloft, with our region near the edge of any heat dome in the Plains. This is a active region any time of year, and one where short waves aloft should arrive periodically. These are difficult to time out at this point, but the outlook for active storm chances continues through mid week, along with seasonally warm/humid conditions in the 80s and dew points values in the lower/mid 70s.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1218 PM CDT Thu Aug 6 2026

Weak convergent winds and ample moisture will continue to keep low clouds as part of our forecast through Friday. The low clouds are generally MVFR to VFR as of 17z, as the scatter out somewhat, but this process will reverse again later tonight, as low clouds and some fog return to the area. There could also be a few very small showers today, but we are not expecting anything other than briefly wetting rains from these. Tonight's fog and low clouds are forecast to be IFR, but could again produce some periods of LIFR fog and VVs around 100 ft, as we saw at DBQ this morning. Friday morning, we're looking at improvement to VFR slowly by late morning, similar to today.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.